From: Mike Galbraith <efault@gmx.de>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
paulmck@linux.vnet.ibm.com, Nadia Derbey <Nadia.Derbey@bull.net>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Pavel Emelianov <xemul@openvz.org>
Subject: Re: Scalability requirements for sysv ipc (+namespaces broken with SEM_UNDO)
Date: Sun, 30 Mar 2008 19:18:08 +0200 [thread overview]
Message-ID: <1206897488.4593.11.camel@marge.simson.net> (raw)
In-Reply-To: <47EF9FC2.3050901@colorfullife.com>
On Sun, 2008-03-30 at 16:12 +0200, Manfred Spraul wrote:
> Mike Galbraith wrote:
> > On Sat, 2008-03-22 at 20:08 +0100, Manfred Spraul wrote:
> >
> >
> >> just the normal performance of 2.6.25-rc3 is abyssimal, 55 to 60% slower
> >> than 2.6.18.8:
> >>
> >
> > After manually reverting 3e148c79938aa39035669c1cfa3ff60722134535,
> > 2.6.25.git scaled linearly
> We can't just revert that patch: with IDR, a global lock is mandatory :-(
> We must either revert the whole idea of using IDR or live with the
> reduced scalability.
Yeah, I looked at the problem, but didn't know what the heck to do about
it, so just grabbed my axe to verify/quantify.
> Actually, there are further bugs: the undo structures are not
> namespace-aware, thus semop with SEM_UNDO, unshare, create new array
> with same id, but more semaphores, another semop with SEM_UNDO will
> corrupt kernel memory :-(
> I'll try to clean up the bugs first, then I'll look at the scalability
> again.
Great!
-Mike
next prev parent reply other threads:[~2008-03-30 16:18 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-21 9:41 Scalability requirements for sysv ipc (was: ipc: store ipcs into IDRs) Manfred Spraul
2008-03-21 12:45 ` Nadia Derbey
2008-03-21 13:33 ` Scalability requirements for sysv ipc Manfred Spraul
2008-03-21 14:13 ` Paul E. McKenney
2008-03-21 16:08 ` Manfred Spraul
2008-03-22 5:43 ` Mike Galbraith
2008-03-22 10:10 ` Manfred Spraul
2008-03-22 11:53 ` Mike Galbraith
2008-03-22 14:22 ` Manfred Spraul
2008-03-22 19:08 ` Manfred Spraul
2008-03-25 15:50 ` Mike Galbraith
2008-03-25 16:13 ` Peter Zijlstra
2008-03-25 18:31 ` Mike Galbraith
2008-03-26 6:18 ` Mike Galbraith
2008-03-30 14:12 ` Scalability requirements for sysv ipc (+namespaces broken with SEM_UNDO) Manfred Spraul
2008-03-30 15:21 ` David Newall
2008-03-30 17:18 ` Mike Galbraith [this message]
2008-04-04 14:59 ` Nadia Derbey
2008-04-04 15:03 ` Nadia Derbey
2008-03-22 19:35 ` Scalability requirements for sysv ipc Mike Galbraith
2008-03-23 6:38 ` Manfred Spraul
2008-03-23 7:15 ` Mike Galbraith
2008-03-23 7:08 ` Mike Galbraith
2008-03-23 7:20 ` Mike Galbraith
2008-03-27 22:29 ` Bill Davidsen
2008-03-28 9:49 ` Manfred Spraul
2008-03-25 16:00 ` Nadia Derbey
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